There are cases where even a simple QR code cannot be read

[site manager]

yes everyone

I'm reading QR codes with Zxiing, but there are codes that can't be read even in the following cases.
Is there any solution
・Simple (short characters)
・Small trimmed
・Sufficient brightness

Used version
javase-3.5.1.jar
core-3.5.1.jar

String charset = "UTF-8";

Map<EncodeHintType, ErrorCorrectionLevel> hashMap
= new HashMap<EncodeHintType,
ErrorCorrectionLevel>();
hashMap.put(EncodeHintType.ERROR_CORRECTION,
ErrorCorrectionLevel.L);

try {
System.out.println(
"QRCode output: "
+ readQR(path+p_fileName_SRCE, charset, hashMap));